Dimensionally Speaking

In mystical context as well as in science fiction, people talk about “other dimensions” frequently and casually—as if that word, dimension, had some kind of concrete reference. Use of that word in a way illustrates how concepts drift. It comes from the Latin dimetri, meaning “to measure out”—and it was used, still is, to indicate measurement. What are the dimensions of this room? Well, they so many feet long, wide, and the ceiling is so-and-so-many feet high. The drift began, according to my source (Online Etymology Dictionary, of course), in 1929. It started to be used to mean “any component of a situation,” thus some aspect of a situation that might be judged separately, on its own merits—as opposed to other aspects. What are the political dimensions of that? Thus, what are those aspects or relationships of the subject under scrutiny.

Now we say that space has three dimensions—but if we think in measurements, that’s not really true. I can measure a diagonal distance as well, thus from the left-hand upper corner at the ceiling to the right-hand bottom corner on the floor. That particular measurement (dimension) is a kind of mixture of the three. But that number, three, is conventionally accepted (except by people who play with fractals). And the playful mind then imagines that there might well be a fourth space dimension—and if a fourth then why not many more? For that to be real, the fourth would have to be at right angles to all three of the usual kind. Now our brain will balk. “Enough already,” it will say. “Can’t picture that. Cannot measure that. And if I can’t measure it, it’s not a dimension.” But people are more than their brains. They can’t imagine it, but they can use a symbol for representing it. And that symbol will work just fine in various equations—and hence we have whole fields of mathematical physics in which such phrases as N-dimensions will be tossed about quite lightly—although the few remaining Large Hadron Colliders, like the brain, simply refuse to bring us any physical proof of such dimensions.

Why mystical scribblers have learned to love the word is quite understandable. They deal with very-tough-to-explain experiences and want to find a place for them—one dimension over as it were. Now as for science fiction writers, they’re up against it too. The nearest star to us is 4 light years away. Light travels at the rate of 671 million miles per hour. Using the highest speed achieved by a manned rocket, Apollo 10, we can just about approach 25,000 mph. But that speed is less than one percent of the speed of light (0.004% to be exact). SF writers therefore must travel a great deal faster than light—but Einstein stands at that gate holding a flaming sword. SF therefore has recourse to the speculations of mathematical physics, produces worm holes that get around the problem, and suddenly the star ships are all over the galaxy in the flash of an eye, and only the galactic rim is a little more distant and takes a few days…

While we’re waxing dimensionally, I must mention Time as a dimension. But is it really? The neat thing about the Familiar Three is that we are free to move in them—now to this side, now to the other. Up then down. We can go back and we can go forth. But time presents a problem. We can only go in one direction. That seems to me a disqualifier. The way Time manages to get a foothold in the respectable society of dimensions is by transforming itself into a symbol, usually rendered as t. Once a symbol it can enter the sacred precincts (or are they dimensions) of abstract thought, marry space to become spacetime, and coyly hint that even time travel is possible if only we could harness the energy of a quasar to power our little time machine.